Kerosene heaters are quite widely used. In fact, you can purchase them at some of the big box retailers in the fall and winter. Some of the brands are Thermoheat, Dyna-Glo, and Champion.
Main Use of Heaters in the US
The main reason, in the United States, for the kerosene heater is as a supplementary use. Some homes have heating problems. For example, it is common to have a cold basement and the only way to add heat to it is to overheat the upstairs. Problems like this can be solved with a kerosene heater because electric space heaters do not usually put out enough heat.
Worldwide Use of Heaters
Worldwide, kerosene is depended on as the only heat and cooking source for millions of people. The reason is that it is economical and readily available. There is no fuel that burns as efficiently as kerosene and the appliances are very inexpensive. With kerosene, you get a lot of btu/hr for the money.
How many BTU do I need?
The btu/hr is determined by the cubic space you are heating, the temperature of the outside, and the insulation of the home. In other words, there is a range and it is hard to get it exactly right. Here is a rule of thumb. For every one thousand square feet, with a home of average insulation, and the outdoors is a colder area, you will need 160,000 to 320,000 BTUs. If you already have central heating and want an additional supplement, then the needs would be significantly lower or about half.